// This file is part of libigl, a simple c++ geometry processing library.
// 
// Copyright (C) 2013 Alec Jacobson <alecjacobson@gmail.com>
// 
// This Source Code Form is subject to the terms of the Mozilla Public License 
// v. 2.0. If a copy of the MPL was not distributed with this file, You can 
// obtain one at http://mozilla.org/MPL/2.0/.
#ifndef IGL_UNPROJECT_TO_ZERO_PLANE_H
#define IGL_UNPROJECT_TO_ZERO_PLANE_H
#include "igl_inline.h"
#include <Eigen/Core>
namespace igl
{
  // Wrapper for gluUnproject that uses the current GL_MODELVIEW_MATRIX,
  // GL_PROJECTION_MATRIX, and GL_VIEWPORT to unproject a screen postion
  // (winX,winY) to a 3d location at same depth as the current origin.
  // Inputs:
  //   win*  screen space x, y, and z coordinates respectively
  // Outputs:
  //   obj*  pointers to 3D objects' x, y, and z coordinates respectively
  // Returns return value of gluUnProject call
  IGL_INLINE void unproject_to_zero_plane(
    const double winX,
    const double winY,
    double* objX,
    double* objY,
    double* objZ);
  template <typename Derivedwin, typename Derivedobj>
  IGL_INLINE void unproject_to_zero_plane(
    const Eigen::PlainObjectBase<Derivedwin> & win,
    Eigen::PlainObjectBase<Derivedobj> & obj);
}

#ifndef IGL_STATIC_LIBRARY
#  include "unproject_to_zero_plane.cpp"
#endif

#endif

